DRM workaround: Kindle for Android

[jberd]

This process seems straightforward enough, except I can't add the backup file to DeDRM. In the options, I can choose "Kindle for Android", and choose the backup file, but then Calibre freezes. Has anyone else had this problem?

[ownedbycats]

Originally Posted by jberd

This process seems straightforward enough, except I can't add the backup file to DeDRM. In the options, I can choose "Kindle for Android", and choose the backup file, but then Calibre freezes. Has anyone else had this problem?

Might be better to ask over at NoDRM github.

[jberd]

Thanks, I'll do that.

[Ma'am-I-Am]

At this time, oldversion.com's servers are not responding.

[Ma'am-I-Am]

Originally Posted by jberd

This process seems straightforward enough, except I can't add the backup file to DeDRM. In the options, I can choose "Kindle for Android", and choose the backup file, but then Calibre freezes. Has anyone else had this problem?

IIRC, Calibre doesn't actually "respond". The .ab filename will just appear next to the "Choose your back up file" button. Once it shows, type a unique name to remind you which key it is.

[ownedbycats]

Originally Posted by Ma'am-I-Am

At this time, oldversion.com's servers are not responding.

Wait a bit (hopefully temporary error), or try different sites.

I don't know of the legitimacy of sites other than oldversion.com. An APK file of version 4.16.0.75 should have an MD5 hash of 1ebe31041db4824c9f83a43d04d74668. If you don't have anything for checking hashes, this site will do it.

If a website tries to download an exe rather than apk, don't open it! (Hopefully obvious, but just want to make sure nobody gets malware'd.)

EDIT: I changed the provided hash to use lowercase letters so that it'll be easier to compare to the website's output.

[ownedbycats]

I updated the original post with the MD5 hash of the apk file and a link to the checksum tool.

[DuckieTigger]

Originally Posted by Ma'am-I-Am

At this time, oldversion.com's servers are not responding.

As of now it does work again. Just remember that oldversion doesn't use https, so if your browser has too strict safety rules, it won't connect.

[AlpineItaly]

Hi, I am using an M1 Mac so I can't run Bluestacks. Can I use this method with Android Developer Studio (electronic eel) which now supports M1.

I have 2 particular worries about this:

1) Does android developer studio (latest version) supports installing ancient apks?

2) Does the commands used to extract the keys work with M1 Macs, since I guess paths etc will be different?

Any reply will be much appreciated.

Many thanks

[DuckieTigger]

Originally Posted by AlpineItaly

Hi, I am using an M1 Mac so I can't run Bluestacks. Can I use this method with Android Developer Studio (electronic eel) which now supports M1.

I have 2 particular worries about this:

1) Does android developer studio (latest version) supports installing ancient apks?

2) Does the commands used to extract the keys work with M1 Macs, since I guess paths etc will be different?

Any reply will be much appreciated.

Many thanks

Yes, you can. You will need to do some legwork for details.

1) Android Emulator (part of Android Studio) can emulate almost anything, so it is not limited to the latest version of Android. Start with a phone or tablet that is capable of running Nougat (randomly chosen, just because it works with Bluestacks). Even Bluestacks "complains" that the Kindle app 4.16 is for an older device. It installs fine after you click the nag screen.*

2) The commands do work just the same - if you use backup adb automatically knows where to backup from. It simply needs the package name. Since by default in Android Emulator the adb shell has root access, you don't need to go the backup route, but simply download the key. (On a real device the adb shell does not have root access, including in out of box Bluestacks).

*It doesn't need Nougat, and it is very picky what processor it emulates. The mentioned Kindle 4.16 from first post does not like any x86 VMs, so the much slower (on my computer) arm is needed. Worked great with Marshmellow with Google for arm (arm64 and x86 didn't work).

[cytoplasm]

Originally Posted by DuckieTigger

Yes, you can. You will need to do some legwork for details.

1) Android Emulator (part of Android Studio) can emulate almost anything, so it is not limited to the latest version of Android. Start with a phone or tablet that is capable of running Nougat (randomly chosen, just because it works with Bluestacks). Even Bluestacks "complains" that the Kindle app 4.16 is for an older device. It installs fine after you click the nag screen.*

2) The commands do work just the same - if you use backup adb automatically knows where to backup from. It simply needs the package name. Since by default in Android Emulator the adb shell has root access, you don't need to go the backup route, but simply download the key. (On a real device the adb shell does not have root access, including in out of box Bluestacks).

*It doesn't need Nougat, and it is very picky what processor it emulates. The mentioned Kindle 4.16 from first post does not like any x86 VMs, so the much slower (on my computer) arm is needed. Worked great with Marshmellow with Google for arm (arm64 and x86 didn't work).

Which device and system image is compatible with the apk?

[DuckieTigger]

Originally Posted by cytoplasm

Which device and system image is compatible with the apk?

The one I mentioned in my footnote. Device doesn't really matter, because every device can run any software, even if the real device cannot do that.

For full disclosure I have picked a Nexus 9 tablet with Marshmallow (Android 6.0 (Google APIs) armeabi-v7a, API level 23) and the Kindle APK that is linked in first post (4.16). All settings were standard when I created it, didn't change anything. And I did not use adb backup. It probably works with backup, but it was slow as molasses on my Windows 11 machine running on Intel CPU (i5-11400, 32 GB ram, everything SSDs). Downloading the keyfile* directly was almost instant.

adb pull /data/data/com.amazon.kindle/databases/map_data_storage.db

That file is less than 100kb in my case.

*little nitpick, that is NOT the key file, just the database it is in. Do what you normally would with the backup file.

[cytoplasm]

Originally Posted by DuckieTigger

The one I mentioned in my footnote. Device doesn't really matter, because every device can run any software, even if the real device cannot do that.

For full disclosure I have picked a Nexus 9 tablet with Marshmallow (Android 6.0 (Google APIs) armeabi-v7a, API level 23) and the Kindle APK that is linked in first post (4.16). All settings were standard when I created it, didn't change anything. And I did not use adb backup. It probably works with backup, but it was slow as molasses on my Windows 11 machine running on Intel CPU (i5-11400, 32 GB ram, everything SSDs). Downloading the keyfile* directly was almost instant.

adb pull /data/data/com.amazon.kindle/databases/map_data_storage.db

That file is less than 100kb in my case.

*little nitpick, that is NOT the key file, just the database it is in. Do what you normally would with the backup file.

Not sure why I'm getting this error when I try to install the apk.
'pm install-create -r -t --user current --full -S 40868769' returns error 'Unknown failure: Error: java.lang.NumberFormatException: Invalid int: "current"'

[DuckieTigger]

Originally Posted by cytoplasm

Not sure why I'm getting this error when I try to install the apk.
'pm install-create -r -t --user current --full -S 40868769' returns error 'Unknown failure: Error: java.lang.NumberFormatException: Invalid int: "current"'

Did you install it with adb? I turned on the Nexus 9, waited until it was finished starting, installed it with (filename abbreviated)

adb install kindle.apk

.

[DuckieTigger]

Originally Posted by cytoplasm

Not sure why I'm getting this error when I try to install the apk.
'pm install-create -r -t --user current --full -S 40868769' returns error 'Unknown failure: Error: java.lang.NumberFormatException: Invalid int: "current"'

You have to replace current with the real number. Use

pm list users

to get it.